This September, OLED no longer “three to five years away”

It's graduation time for organic LED displays, as the technology moves out of …

As of next month, it will be our pleasure to move organic LED (OLED) displays out of Ars's informal "three to five years away" category, where it will join fellow 3t5YA alumnus E-Ink in the mass market. Right now, there's a trickle of OLED-sporting devices poised to come to market in the fourth quarter of this year, but economies of scale should take hold and the screens should get cheaper, turning that trickle into a flood. But the shift to OLED will have some unexpected consequences for battery life, which in general will be better than it is for LCD-based devices—with a caveat.

We've already seen OLED in some boutique devices like the now-defunct OQO Model 02, but OLED's true break-out product will be the forthcoming Zune HD. The device, which is slated for a September launch, has an 3.3" active matrix OLED (AMOLED) touchscreen that's already generating excitement, even among some die-hard iPhone fans. Then there's the new Nikon Coolpix S70, also launching in September, which sports a 3.5" OLED touchscreen that covers the entire, buttonless back of the device.

If rumors are to be believed, Samsung's OLED-packing Omnia II may get the jump on September with an August 23 release date. This will be but one of a number of OLED devices planned by Samsung, which has invested heavily in the technology. Some of these Samsung products are destined for Sprint's network sometime in the fourth quarter, where they'll team up with the Pre as part of Sprint's effort to lure customers away from the iPhone.

LG is also a big OLED backer, and is rumored to be planning a December launch for its 15" OLED display in Korea. Don't bother saving up for one of these, though, because a panel this size will be a multiple of the price of a vanilla flat panel. OLED has a barrier to jump before it makes sense at larger sizes, since companies like Samsung will have to shell out to get fabs for the larger panels up and running. Don't expect that process to start until global credit markets loosen up and consumer demand for premium products returns.

One of the big variables with OLED displays is battery life—an OLED's power consumption varies greatly with the gray level of the image it's displaying. Bright images with low gray levels consume much more power than darker images with higher gray levels, as shown by the slide below, which came from a May 2008 OLED presentation.

Though it's not apparent from the slide because of the selection of sample patterns, power draw varies pretty linearly with mean gray levels, and the range is fairly wide. This inconsistency may have some implications for interface design.

For instance, black backgrounds will be the rule on these devices, and it's likely that e-book apps may end up using white text on a black background. I imagine that video playback will probably even out, so that most videos will end up drawing similar amounts of power. Ultimately, though, what's on the screen will have an impact on battery life, and will give mobile users one more variable to tweak in their never-ending quest for a few extra minutes of usage time.

OK, so what you;re saying is content being displayed has an impact on power draw... Well, if the power draw is still less than LED across the board, then is it really that big of a deal???

The real question is when will the cost of the panels plus 3-5 years of power savings reach a price point where the TCO vs LCD becomes lower, or at least close? When I can get deeper blacks and a sharper diaplay for reasonably close to the same TCO, that's when it might be worth the switch.

In mobile devices where battery life is a major concern, I don't really know that OLED will really make that big of a difference. The screen is a power hog, sure, and if you play a lot of video on your mobile phone that could be a concern, but i doubt that we're really talking about more than a 15-20% average battery gain, and odds are they'll just make smaller batteries and lighter devices instead of actually extending use dramatically.

Personally, I don't really care about screen thickness. The LED backlit displays are already rediculously thin, and to a point, going thinner is not detracting from durability and I'm concered that going thinner wil be dramatically shortening device lifespan.

So whenever you look at a website, or a document, you use more than three times the power of a TFT. That's quite often, if you're like me.

And that's assuming the brightness is the same.

Mobile TFTs are partially transflective and can use ambient light to increase the brightness - it doesn't all need to come from the battery.

Plain fact of the matter is that, in real world mobile devices, OLEDs use much more power than TFTs.

And you cannot read them at all outdoors on a bright day when a TFT is readable.

And the contrast ratios are actually no higher than a good TFT indoors.

And the OLED pixel efficiency drops rapidly so you need even more energy to produce the same amount of light.

And the blue pixels fade faster than the others, so your colour goes off quickly.

So all round, it's a worse product for mobile devices.

Basically OLEDs have received a lot of hype and so Samsung know they can sell a lot of units based on that amount, despite the fact that, technically speaking, they're worse in a mobile product than a TFT.

There are sadly plenty of people who will pay more for a worse product if they've been told it's better (by people who have a vested interest).

When the LCD manufacturers solve the problem of how to colour pixels without sticking a filter in front of the display that blocks 2/3rds of the light, like PixelQi are working on, then TFTs will massively leapfrog OLEDs in terms of performance and power efficiency and will remain much, much cheaper to make.

TFTs require more layers than OLEDs and are due to their mechanical nature (crystals) quite inflexible. There's also no conceivable way to print the structures of a TFT as they are far too complex.

Back to OLEDs... OLEDs have been used in mobile phones and some portable media players for years now, so I find this article a tad odd. The LG 15" OLED TV is the biggest thing ATM considering it's a newer generation (3rd?) of OLED screens compared to Sony's 11" OLED TV and should be the first practical one. In that sense OLED is maturing.

In mobile markets OLED has been making headway for a while now, is wiping the floor with LCDs and is getting more and more power efficient with longer durability. Just give it some time

I don't get it. The Zune HD has a significantly smaller and lower resolution display than the iPod touch, even though the device itself is bigger.

The Zune can decode HD content, but you need an external screen to display it, so what is the point of that feature? When are you going to stumble across a brand spanking new HD display, but no HTPC or other media device to supply it with HD content?

The Zune reviews I've seen make a big point of claiming that the Zune finally has a usable web browser, which the iPod has had for a few years.

The Zune has a bunch of other features, like radio support, that either very few people actually use, or that can be added to the iPod through an App Store application.

The Zune comes with more storage space, and there is a chance it will have better battery life, but overall, it seems to be a significantly worse device than an iPod touch for very nearly every use case.

I don't mean to troll, I'm guessing I'm missing something, because the HD is getting quite a bit of hype, but I honestly think it looks like a pretty lame device. Can anybody give a decent explanation of who, other than Steve Ballmers son, should get a Zune HD instead of an iPod touch?

Originally posted by mathrockbrock:I thought some potential benefits of OLED were flexible displays, transparent HUDs, faster response time, and ability to print them with inkjet-type processes. Would any of that be possible with TFT?

The wikipedia page on OLEDs is a hopeless, ill-informed love-fest based on very little evidence.

You can do flexible displays with LCD too, but flexible displays are also always 3-5 years away I've seen prototypes of them for years and they're always rubbish: fragile and uneven.

For transparent HUDs, yes, OLEDs would work OK, but they're really incredibly nichey. We're talking about suitability for hundreds of millions of phones and other mobile devices shipped each year.

Do you really need a faster response time than 240Hz that TFTs are already at? I find 60Hz quite fine.

The whole thing about printing the displays with inkjets is misleading. The inkjet only dumps down the organic substance that emits light, not the transistor to control it.

What do you need to print them onto? A TFT substrate, which has to be made lithographically, just like for LCDs. Except even harder to do than LCDs...

On an LCD, you only deliver a tiny switching current to each pixel. OLEDs you need to supply a large current to actually illuminate that pixel. That means bigger wires and more efficient transistors.

To get the low resistance you need for all of that means you cannot use amorphous Silicon (A-Si) and must instead use a poly-crystalline Silicon substrate (P-Si), which is much more expensive as you have to do something like anneal the glass with a laser. LTPS is the chosen process for this generation of AMOLEDs.

Furthermore, the inkjet process is expensive, slow and less accurate - it's pipedream stuff at the moment that makes for nice easy reading.

The manufacturing method for LCDs has an installed and proven infrastructure worth billions.

And you don't buy a display because it's been printed. Hopefully you buy it because it's good... and the fact is that the OLEDs don't provide any real world advantage and do carry lots of disadvantages for mobile devices.

The thing is, the Omnia HD had an AMOLED screen. I went and played with one at an Orange shop. The screen was gorgeous and vibrant. I wish they would bring the TVs out soon because I'll be in the market for one in the next year. If not, I'll just have to get one of those LED backlight TVs from Samsung. The picture on those seems to be really pretty. Can't say the same for the sound, but what do you expect from a TV less than an inch thick?

Do you really need a faster response time than 240Hz that TFTs are already at? I find 60Hz quite fine.

We don't actually even need 60Hz. A Hollywood movie is, I beleive, ~25 fps, which is going to be quite a bit less... All older console games, and pretty much most modern ones are averaging closer to 15 fps, that's plenty for those.

So why would I need faster then a display that refreshes faster then 15 times per second?

Answer is: I don't _need_ it. But I like having it.

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The manufacturing method for LCDs has an installed and proven infrastructure worth billions.

And you don't buy a display because it's been printed. Hopefully you buy it because it's good... and the fact is that the OLEDs don't provide any real world advantage and do carry lots of disadvantages for mobile devices.

Can anybody give a decent explanation of who, other than Steve Ballmers son, should get a Zune HD instead of an iPod touch?

It's not going to take out the iPod Touch, and I think most people know that. The iPod has a massive app store and it's likely going to get a camera and (IMO) will get a 64 GB capacity in September, so the Zune HD will once again be the lesser device by a significant margin.

To answer your question on who would buy one, I see it like this:-MS fanboys-People who hate Apple for whatever reason-Non-conformists who feel that they'll be different by getting a Zune over and iPod.

So why would I need faster then a display that refreshes faster then 15 times per second? Answer is: I don't _need_ it. But I like having it.

But I hope you would accept that there is a point at which your eyes cannot possibly perceive any improvement in refresh rate - they are the limiting factor. 120Hz+ is easily possible with today's TFTs and that is way higher than what you can see. Therefore any theoretical advantage OLEDs may have response time is meaningless.

Well, yes, of course I would, but you're simply not describing an OLED there.

Longer battery life is always good, naturally. But real world use says OLEDs get a shorter battery life unless you are spending most your time looking at black content! Maybe they're best for goths

They're not easier to read as they are 100% emissive. Generally, the more natural light a display reflects, while maintaining a decent contrast ratio, the easier it is to read, which is why e-paper is best in this respect: it is 100% reflective.

And when you go outside and have to deal with the fact that the sun is a lot more powerful than an OLED pixel, it is completely unreadable (as I'll show you later).

OLEDs also don't have "vastly superior colour depth", by which I presume you mean colour space reproduction compared to good LCDs. In fact, the best TFT with an RGB LED backlight will reproduce a wider proportion of the colour space than the best OLED ever could.

Those figures are essentially lies. Even the OLED makers are now giving more honest figures closer to 4000:1 (I'm reading that right now from a Samsung OLED datasheet).

The high CRs of OLEDs depend on being used in a completely black environment... Contrast ratio is defined as the brightness of a 100% white screen divided by the brightness of a 100% black screen.

So, yes, in a dark room, the OLED will look better. That's why I want one for my TV

Take your mobile phone, display off, and look at the screen: you may notice that it is not completely dark: it's not a black hole absorbing all the light - it reflects some of the light from the surroundings, whether a glossy or matt panel. The brighter the room, the brighter that black screen gets.

Because the OLED's white screen relies 100% on the LED power, it stays the same. Same number divided by much bigger number = lower contrast ratio.

Here comes the maths.

On the display that they show you, the OLED produces 200nits (cd/m^2) of light. The brightness of outdoor light on a sunny day is around 50,000 nits. The surface of the display will reflect about 4% of that, so 2,000 nits. Add those together and you've got your white screen brightness.

Therefore your contrast ratio for the OLED becomes 2,200 / 2,000 = well, about 1.1 to 1. That means that the whites are only 10% brighter than the blacks, which is frankly not even close to readable, let alone "True 1,000,000:1"

On a transflective TFT, say one that only reflects just 20% efficiently, the brighter the environment, the brighter the whites get at the same time, and so the contrast ratio holds up much better.

The white screen will be 50,000 * 20% = 10,000, + the 200 nits from the backlight and the black pixels will be the same 2,000 nits of surface reflection plus about 0.5nits that leaks through the LCD (based on a 400:1 contrast ratio, 200 nits backlight).

Therefore the contrast ratio for the LCD = 10,200 / 2,000.5 = about 5:1. Still not great but readable. And nearly 5 times better than the OLED.

Furthermore, if you remove the colour filter and use a coloured backlight, that 20% reflectiveness goes up massively and you are left with a brilliantly readable display, almost as good as e-ink, albeit predominantly black and white.

LCDs can be improved in this respect in any number of ways, but the OLED is inherently stuck - it is unsuitable for use outdoors unless you rack that brightness up to about 2,000 nits (and then watch your battery burn out in 2 minutes)

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You can keep your bland, washed out LCD displays to yourself.

I think the problem most people have with LCDs is that they've only really ever seen bad, cheap ones. If you compare a $10 TFT to a $40 OLED, then it's not really fair. But compare a $25 TFT to a $40 OLED and you won't get the same result - the TFT will almost look as good indoors but will be useful everywhere. And it's still much cheaper.

At the end of the day, pick the device that you like based on what you want to use it for. If you're going to be watching lots of movies in bed, are agoraphobic, or live in a country with no sunshine, then an OLED device would be fine for you.

For me, the compromises of worse battery life, the speed at which the display loses quality and brightness and the compromise of losing any use of the device outdoors is personally too much for a portable device that I do need to use outdoors for navigation, reading, looking up information, controlling my music playback, seeing who is calling me, sending text messages / e-mails.

To all the doubters; honestly, why would these companies be investing so much money in OLED when they aleady have mature LCD capability unless it had some hefty advantages? If it was just marketing crap, they would find some other attribute to fixate on that didn't cost billions in new plant.

I don't have any technical knowledge of LCD vs OLED, but your argument that is actually worse than LCD just doesn't hold water.

We've already seen OLED in some boutique devices like the now-defunct OQO Model 02, but OLED's true break-out product will be the forthcoming Zune HD

The current (from June?) Sony and Cowon flash-memory music/movie players use OLED screens. How is the upcoming Zune the break-out product? It's no less of a "boutique" device than the Sony or Cowon players...

Sorry to raise this again (I really am), but is this just Ars brand preference?

I'd get a zune, but it would really be for the hd radio. I'm pretty sure you cant get an app that wil install an hd radio reciever in your ipod. You would have to stream it through the network.

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Originally posted by sword_9mm:

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What console games do you play? Mine run at 60 FPS (with a few at 30 FPS).

you must not be using a ps3/360. most games can barely keep up with 30 and seem to dip quite a ways toward 10 in some it seems.

guess you're using a pc?

I dunno what console your playing, maybe a snes, but a 10-15 fps is ussually considered unplayable by most people. Your eyes percieve the world at about 25-30 fps. You might want to get a new console if that is what your actually achieving. 360 and ps3 games are ussually designed to put out an average of 30 or 60fps with some cinematics taxing the system and dropping abit. The easy way to tell is reading the back of the game where it says what it displays at. if it goes at 1080p then its displaying at 60hz and 60fps if its 1080i then 30hz and 30fps.

Do you really need a faster response time than 240Hz that TFTs are already at? I find 60Hz quite fine.

We don't actually even need 60Hz. A Hollywood movie is, I beleive, ~25 fps, which is going to be quite a bit less...

Film is shot at 24 fps (PAL TV is 50 fps interlaced and NTSC TV is 59.94 fps interlaced).

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Originally posted by drag:All older console games, and pretty much most modern ones are averaging closer to 15 fps, that's plenty for those.

So why would I need faster then a display that refreshes faster then 15 times per second?

Answer is: I don't _need_ it. But I like having it.

The main reason you'd actually want higher fps on your display for games is that games don't add any form of motion blur. Thus if it's running at a low fps, your brain sees it as a slideshow instead of continuous motion. Add in proper motion blur and games could get away with the same 24-30 fps that movies and TV do. Of course, to calculate said motion blur, they would need to have those in-between frames to blur (or motion compensate between the frames it does render), all of which is pretty computationally heavy. So it is far easier to just shove 60 fps out and let your brain just smooth it over.

Originally posted by sword_9mm:heh. i thought this was about actual oled tv's. they are still 5yrs away i guess. zune hd makes me laugh as well. zune. oh microsoft you funny guys.

Why does Zune make you laugh? They are nice players at good price points. The only reason anyon can ever give me for laughing at them is that they are not as popular as iPods. I don't know about you but I personally don't care about this bandwagon tendency to scoff at things that are less popular regardless of their merits. It just makes you sound smug and annoying. I have used both Zunes and iPods (as well as other brands of PMPs) and I've not found Zune to be lacking in anything really. My Zune does everything my girlfriend's iPod does and it cost less and has a radio for when I want to listen to NPR. A nice OLED screen is just an added bonus if you ask me.

I dunno what console your playing, maybe a snes, but a 10-15 fps is ussually considered unplayable by most people. Your eyes percieve the world at about 25-30 fps. You might want to get a new console if that is what your actually achieving. 360 and ps3 games are ussually designed to put out an average of 30 or 60fps with some cinematics taxing the system and dropping abit. The easy way to tell is reading the back of the game where it says what it displays at. if it goes at 1080p then its displaying at 60hz and 60fps if its 1080i then 30hz and 30fps.

some games run at 60, some run at 30, the majority run at 30 with frequent dips in the 20's or lower. try gtaIV sometime. hz means nothing to framerate man. i run hl2 at 60hz but get maybe 20 fps on my pc. hz means nothing.

Originally posted by embedded:Basically OLEDs have received a lot of hype and so Samsung know they can sell a lot of units based on that amount, despite the fact that, technically speaking, they're worse in a mobile product than a TFT.

Sort of like LCDs did in the 90s? Remember LCDs in the 90s? They were absolutely terrible. The only reasons to get one were because it was thin, and people knew you had spent a ton of money on it. It's only been in the past few years that LCDs have finally really good for most things.

I had one of the first phones with a color LCD display, and it was completely unreadable outside. The progress since then has been amazing, and now black and white LCD phones are almost non-existent.

OLED displays have the potential to become significantly easier to produce, including at large sizes. Once they've been in the mainstream for 15 years, I imagine that most of the complaints will be dealt with. The efficiencies will get better, the light will get brighter, the life will get longer, and they will become cheaper to make. The big companies all know this, which is why they are working so hard to get there.